Digital microphone technology on stage. The sound of the Neumann vocalist microphones connecting to AES 42, AES/EBU and S/PDIF.

The Digital Microphone Interfaces in general

Equipment that supports the AES 42 standard can process the output signals of Solution-D microphones directly. In all other cases, the DMI-2 portable or DMI-8 digital microphone interface is used. The DMIs convert the AES 42 data format supplied by the microphone into an AES/EBU signal.

The Interface is operated and the microphone parameters are controlled via the Neumann RCS remote control software, which is installed on a desktop or laptop computer. The computer is connected to the DMI via a USB port and a USB to RS 485 interface converter. If a large number of microphones is used, several DMI-8's can be cascaded. In this case, each digital microphone interface can be addressed individually.

In addition to a word clock input and output, the DMIs also have an internal word clock generator. If no master word clock signal (e.g. from a mixing console) is present at the input, the DMI internal word clock is used automatically to synchronize the microphone channels, and the signal is switched to the word clock output.

External commands such as "On Air" (red light) can be controlled via a 9-pin user port.

The DMI-8, an eight-channel version of the digital microphone interface is considerably simplifying the setup for multichannel applications.

In addition to the proven functions of the two-channel DMI-2 portable the DMI-8 also offers the following features:

- The capability of cascading up to 128 channels- D-sub 25 outputs with Tascam® and Yamaha® pin assignments- Optical ADAT® interface- Open architecture for later connection to other multi-channel interfaces and audio networks, such as EtherSound® and MADI

The DMI-8 offers several possibilities for easy integration into audio networks. The ES100 (DMI-8) module permits integration into EtherSound networks.

Explanation Mode 2:The DMI performs a frequency/phase comparison between the word clock signal recovered from the mic signal, and the word clock of the DMI. From the phase deviation thus determined, the DMI calculates a control signal which is transmitted via the remote control data stream to the mic, where it controls the frequency of the internal quartz oscillator.

1 x RJ 45 (special serial data format developed by GN, used as a gateway for integration in audio networks. The GN signal will be used by Neumann’s Multi Channel Audio Interface (MCA) for converting of the GN data format to formats such as EtherSound®, MADI, etc. (MCA available as option)

- The AES/EBU signal includes 2 audio channels - The distribution of the audio data of adjacent mono microphone channels between the audio channels of the corresponding AES/EBU output signal is as follows:

Channel 1 AES/EBU out

Left: mic 1 Right: mic 2

Channel 2 AES/EBU out

Left: mic 3 Right: mic 4

Channel 3 AES/EBU out

Left: mic 5 Right: mic 6

Channel 4 AES/EBU out

Left: mic 7 Right: mic 8

Digital stereo microphones are supported at odd numbered AES42 microphone inputs only. In this case the audio data of the microphone are routed to the left and right channels of the corresponding AES/EBU output.